The present invention relates to locked oscillators and more particularly to injection locked oscillators.
Injection locking of oscillators is a well known phenomenon where the oscillating frequency of one oscillator is locked to the oscillating frequency of another oscillator such that the output of the injection locked oscillator has a frequency harmonically related to the frequency of the oscillator to which it is locked.
The basic technique of injection locked oscillators using fixed frequency oscillators has been used at high microwave frequencies to realize functions such as signal amplification, frequency division, frequency multiplication, synchronization of two oscillators and providing a clean signal from an oscillator injection locked by a noisy oscillator. The injection locked fixed frequency oscillators of the prior art, however, suffer from a relatively narrow frequency range of reliable operation. This is due to the inherently narrow frequency range of fixed oscillators.